Mounting arrangement for a high voltage electron tube



March 15 1966 H. DEQK MOUNTING ARRANGEMENT FOR A HIGH VOLTAGE ELECTRONTUBE Filed Jan 29, 1962 INVENTOI? HAROLD DECK I I'E EH |||l| I 24% 2ePATENT AGENT United States Patent 3,241,093 MOUNTING ARRANGEMENT FOR AHIGH VOLTAGE ELECTRON TUBE Harold Deck, San Jose, Calif., assignor toComponents for Research, Inc., Palo Alto, Calif., a corporation ofCalifornia Filed Jan. 29, 1962, Ser. No. 169,486 3 Claims. (Cl. 336-407)The present invention relates generally to the installation of electrontubes, and more particularly to a mounting arrangement for high voltageelectron tubes wherein the high voltages may appear both at the anodeand cathode of the tube.

Both the installation and subsequent maintenance of electron tubes whichoperate at relatively high potentials (e.g., thirty kilovolts) arecomplicated by the necessity for avoiding the possibility of voltagebreakdown between the various elements of the entire circuit. Forexample, in the installation of a conventional high voltage rectifiertube, it is not only necessary that a filament transformer be utilizedto isolate the high voltages applied to the tube from the source offilament voltage but it is additionally necessary to mount such filamenttransformer within a bath of insulating oil to enhance insulation of thehigh voltages which exist between the primary and secondary windings ofthe filament transformer. Obviously, a container for the oil bath isrequisite and such container in turn presents the necessity for theemployment of suitable bushings which not only provide electricalinsulation but a mechanical seal as well. Not only is such initialinstallation of the high voltage rectifier and its associated circuitryrendered extremely complex and tedious, but subsequent maintenance isalso difiicult and time-consuming.

Accordingly, it is the general object of the present invention toprovide a mounting arrangement for high voltage electron tubes that isnot only effective to avoid breakdown at the high operating potentials,but simplifies both installation and maintenance.

More particularly, it is a significant feature of the invention toprovide a mounting arrangement for an electron tube that embodies asolid insulator which not only isolates the various circuit componentsbetween which high potentials exist but also functions as a base for theelectron tube socket to thus provide a unitary mounting arrangement.

Additionally, it is a feature of the present invention to provide amounting arrangement for an electron tube which embodies a solidinsulator within which a filament transformer can be embedded to moreeffectively preclude voltage breakdown between the primary and secondarywindings of such transformer.

Furthermore, it is a feature of the present invention to provide amounting arrangement for a high voltage electron tube that not onlyhouses the filament transformer and provides a mounting for the base ofthe electron tube, but also incorporates terminals which facilitateconnection of the appropriate external circuitry.

Yet another object of the invention is to provide a unitary mountingarrangement for a high voltage electron tube that is relatively compactand inexpensive and can readily be transported and installed.

These as well as additional objects and features of the invention willbecome more apparent from a perusal of the following description of thestructure illustrated in the accompanying drawing wherein:

FIG. 1 is a side elevational view of a mounting arrangement for a highvoltage electron tube in accordance with the present invention, portionsof the structure being broken away to illustrate interior details of thearrangement, and

FIG. 2 is a fragmentary top plan view of the structure illustrated inFIG. 1.

With initial reference to FIG. 1, the mounting arrangement for a highvoltage electron tube constituting one embodiment of the presentinvention is illustrated in its normal upright disposition wherein aslightly tapered but generally cylindrical insulator 10 is disposedbetween a first annular conductor 12 at its lower end and a secondannular conductor 14 at its top or upper end.

The unit is preferably formed by vacuum casting of an epoxy resin toform the insulator 10 between the two annular conductors 12, 14. Asshown, the casting is formed about a suitable filament transformer 16 sothat such transformer is completely embedded in the interior of theinsulator. Such filament transformer 16 is shown only in outline sinceit is of more or less conventional nature, but it will be appreciatedthat the excellent insulating properties of the epoxy casting willeffectively isolate the primary and secondary windings 16a, 16b, of thetransformer to preclude voltage breakdown therebetween. The wire leads18, 20 from the primary winding 16a of the transformer 16 extenddownwardly through the insulator 10 and through the opening formed inthe central portion of the lower annular conductor 12 and then laterallyoutwardly through another insulator 22 to suitable terminals 24, 26which enable connection of a filament voltage source (not shown)thereto. A fiat metallic plate 28 is located at the lowermost end of thestructure to facilitate mounting of the entire unit and tosimultaneously provide an electrical ground connection.

The secondary winding 16b of the transformer 16 includes wire leads 30,32 that extend upwardly through the insulator 10 and through the centralopening in the upper annular conductor 14 for electrical connection totwo terminals 34, 36 of a conventional tube socket, generally indicatedat 38 so that filament voltage derived from the secondary of thefilament transformer 16 can be applied to the filament of an electrontube which is merely indicated in phantom lines in FIG. 1 and can, ofcourse, be a tube of any selected type. One of the filament terminals 34is connected to the annular conductor 14 at the top of the insulator andaccordingly, this upper annular conductor will be subjected to the highpotentials applied to the cathode of the tube. Preferably, as shown,this annular conductor 14 is rounded on its periphery so that no sharpedges will create points of excessive electric field strength.

The structure of the tube socket 38 is conventional and will, of course,vary depending upon the electron tube that is to be mounted andtherefore will not be described in detail; but, as best shown in FIG. 2,can be centrally secured in a suitable fashion to the top of themounting arrangement so that the upper annular conductor 14, which hasgreater lateral dimensions, will effectively shield all exposed highpotential connections to the tube socket or the tube itself from the lowpotential elements at the lower end of the structure.

Quite obviously, the precise dimensions of the unit and particularly thelength of the insulator will vary depending on the potentials to beapplied; and moreover, the shape of the entire unit may be varieddepending on particular requirements. By way of example, for mounting ofa rectifier tube designated as type 8020 and having an inverse peakvoltage rating of 40 kilovolts, the insulator 10 will be approximately9.5 inches in length and the unit can be supported in an airenvironment. For an extremely high voltage rectifier tube such as typeML 141 having an inverse peak voltage rating of kilovolts, the length ofthe insulator 10 should be approximately 12 inches and should beimmersed in oil. However, because of the preassembled unitary nature ofthe tubemounting arrangement, as described, initial installation andsubsequent maintenance are greatly simplified even under the conditionsof oil immersion.

Accordingly, the foregoing description of one embodiment of theinvention is to be considered purely as exemplary and not in a limitingsense; and the actual scope of the invention is .to be indicated byreference to the appended claims.

Whatis claimed is:

.1. Mounting arrangement for a high voltage electron tube whichcomprises a solid insulator having a filament transformer embedded.therein, a first annular conductor at one end of saidinsulator,conductive means extending through said annular conductor'into said insulator and connectedto the primary winding of saidtransformer, a second annular conductor having a rounded contour at theother end vofsaid insulator, atube socket mounted on the side of saidsecond" annular conductor opposite to said transformer and'havingfilament terminals, and conductive means connected to said filamentterminals of said socket and extending through said'annular conductorinto said insulator and connected to the secondary Winding of saidfilament transformer.

References Cited by the Examiner UNITED STATES PATENTS 1,705,559 3/1929Dubilier 339193 X 1,796,421 3/1931 Apple 336-96 2,279,635 4/1942 Morley336-105 X 2,971,145 2/1961 Enge 336-208 X OTHER REFERENCES ElectronicDesign Magazine, May 1955, pp. 31-33. Tele-Tech and ElectronicIndustries Magazine, July 1956, p. 58.

JOHN F. BURNS, Primary Examiner.

1. MOUNTING ARRANGEMENT FOR A HIGH VOLTAGE ELECTRON TUBE WHICH COMPRISES A SOLID INSULATOR HAVING A FILAMENT TRANSFORMER EMBEDDED THERRIN, A FIRST ANNULAR CONDUCTOR AT ONE END OF SAID INSULATOR, CONDUCTIVE MEANS EXTENDING THROUGH SAID ANNULAR CONDUCTOR INTO SAID INSULATOR AND CONNECTED TO THE PRIMARY WINDING OF SAID TRANSFORMER, A SECOND ANNULAR CONDUCTOR HAVING A ROUNDED CONTOUR AT THE OTHER END OF SAID INSULATOR, A TUBE SOCKET MOUNTED ON THE SIDE OF SAID SECOND ANNULAR CONDUCTOR OPPOSITE SAID TRANSFORMER AND HAVING FILAMENT TERMINALS, AND CONDUCTIVE MEANS CONNECTED TO SAID FILAMENT TERMINALS OF SAID SOCKET AND EXTENDING THROUGH SAID ANNULAR CONDUCTOR INTO SAID INSULATOR AND CONNECTED TO THE SECONDARY WINDING OF SAID FILAMENT TRANSFORMER. 